# Professional Measurement and Estimation of Roofing

The geometric roofing estimator space is in squares. Being accurate with the roofing measurements is very important if you do not want to get stuck with additional thousands of dollars in roofing budgets.

With the use of a hypothetical example, it is explained below how you can use mathematical formulas to calculate a triangle for measurement. A simple mathematic calculation will help you estimate the triangle for an average roofing example.

**1 Roof square:**

100 square feet; the length of the height of a triangle amounts to twice the area of the triangle. Rearranging this equation, you can find the area of a triangle by calculating the product of height and length and then dividing it by 2 to get the area.

In this particular example the length=30 feet, the height = 12 feet. According to the formula, the area of a triangle makes up 180 square feet

This example will clear out the basic concept of calculating the area of roofing. Let’s look at a more complex example, now shall we? In the diagram given below, you will be able to see both the hip-end section and the gable ends of the roofing. This is an example of a much more complex roofing system. In professional environments, the start off for such a roofing system is a sketch that gives an on-paper view of the roof. This essential first step helps with calculating the measurements and determining the material that is needed to complete the roofing. The best way for on paper calculations of the area of the roof is to break the roof up into parts from A to E.

Figure B:

Figure B shows a triangle-shaped part just as there was in the previous sketch of the roofing figure. As done before you will measure the length of the eave and then draft a vertical line through the halfway point all the way to the peak. This is going to give us the height of the triangle. You will multiply these numbers and then divide the answer you get by 2.

Figure C

The much simpler way to measure this portion is by dividing it into sub-parts the S1, S2, and S3, and all these parts will be of the same size. The actual measurement of the roof will give you the accurate measurements that you need to calculate area on Paper. S2 is a rectangular shaped sub-part and it is easily measurable by multiplying the length with the Width of the roofing portion.

The portions are:

**S1= **(18’x15’)/2= 135 square feet

**S2=** 50’x15’=750 square feet

**S3=** (18’x15’)/2= 135 square feet

The total of these three sections when added up will make up for= `1,020 square feet

Figure D

Once again, we will be dividing up the roof again to measure the roof. Apart from the previous calculations, you will be measuring eave to ridge and rake to the valley for the S4 and S5 sections. Sections S6 and S7 mark the portion between the eave end and the valley end as well as eave to ridge.

**S6= **(18’ x18’)/2= 162 square feet

**S7=**(18’x18’)/2=162 square feet

You may even apply a different method of calculation directly from the equation, the two 18 lengths in S6 and S7 can be calculated to give 36 then the two 18 widths can be calculated to give the width. You can divide them by 2 and get a 324’ area for both S6 and S7.

For the S1 and S2 parts, you will be able to calculate the total length of the rake side and then find its product with the eave to get the final answer

18’+18’= 36’ x 30’= 1080 square feet

Total for Fig C: 324’ + 1080’ =1404 square feet

Fig E:

This is when we will make use of S9 18’ x 10’=180’ and S8 (18’x18’)/2= 162’ for a total of 324 square feet.

The last two sub-parts are measured as follows:

96’x 18’= 1728’ and (18’x18’)/2= 162’ for a total of 1890 feet

**This makes the total sum of Roof calculations: **

Now you can take the totals of all the figures and add them up:

Figure A= 270’

Figure B=1,020’

Figure C= 1,404’

Figure D= 324’

Figure E=1890’

**Total= **4,908 square feet

This will make roughly 50 squares, 1 square is equal to 100 square feet.